Got back together with my ex, but I still have some conflicting feelings?

Long story short we are both seniors in highschool and we started off as friends freshmen year. We Bagan dating sophomore year, and we're together for almost two years, but I broke it off about 4 weeks ago because of several problems. We had a model relationship and there were no severe problems, but we have our differences. I couldn't move on because we still see each other all the time at school and we do the same extracurricular activities. We decided to remain friends, but I decided to talk to her today to see if we can give it another try because I can't just give up and walk away that easily. We agreed to start the relationship as if it were new again, and that if it doesn't work this time then we will not hold anything against each other and will go our separate ways knowing that we tried. I feel much better knowing that I'm giving it another shot, but I have very little hope that we will be successful, and I have that tiny hope in the back of my head that it won't work, but I truly do want it to work.

Updates:

Wow I didn't mean to contradict myself in that last sentence. I meant to say that I truly want to give it another shot. I guess I'll give it a month and see how it goes.